TBH, if I found those things annoying enough to seek out this library, I would probably just use Clojure or some other language.
Not that CL couldn't use cleaning up. But to really make the new dialect popular, you'd have to focus on attracting new users, which would require things like writing books, or at least updating some of the existing books (e.g. Peter Seibel's). In short, defining and implementing the new dialect is only the first step of a long slog.
It's my observation that CL regularly attracts new users, who grumble a bit at first and then fall in love. Then they drift away to other langs, keeping an affection for sexps, macros, and the numerous elegant aspects of CL. But drift away they do. IMO, if CL could keep more of the people who learn it well enough to love it, then it would be thriving. I have some opinions on why people drift away and how that could be addressed but they're not especially well formed at this time.
I dream of meeting someone who wants to build something like mesos on top of cells.
I would like to hear them nonetheless.
Instead, here's one of the things that started me thinking about this... Some years back, Xach created the library manager Quicklisp, filling a huge hole in the lisp ecosystem. It's nice work and quickly became the defacto standard. Lots good to say about it and nothing bad, really. The thing that got me thinking was that this actually needed to be done at the time Xach did it. CL had been around a long time officially and even longer unofficially, and this really important piece of infrastructure had not been done. How could that be?
"How could that be?" leads to more questions, and possible answers, and some loose ideas about moving forward. That's where I'm at, and I don't want to say more until I have something concrete and constructive. I wouldn't mind having a speculative conversation (that would help me greatly), but I think throwing out half baked ideas would do nothing more than the existing corpus of "why lisp isn't successful" blog posts, so I don't want to have that conversation somewhere like HN.